Classroom activity Grade 1 Science

Clean Creek Patrol at Larkspur Creek: A Grade 1 Activity

A grade 1 activity where two teams collect litter near a model creek, count what they gathered, and add their totals together.

Grade: Grade 1
Subject: Science
Material: Classroom activity
Time: 35 min
Prep: Low prep
Materials: Twelve paper cutouts: seven litter items (bottle, wrapper, can, foil, cup, straw, bag) and five natural items (leaf, twig, feather, pebble, pinecone), Blue tape or a strip of blue paper to mark the model creek, Two labeled bins or hoops, one per team, A timer

Standards

K-2-ETS1-1 NGSS

Ask questions, make observations, and gather information about a situation people want to change to define a simple problem that can be solved through the development of a new or improved object or tool.

How this material aligns: The opening discussion has students ask questions about why litter is a problem for the plants and animals near Larkspur Creek, defining the problem before the patrol begins collecting.

All materials for K-2-ETS1-1 →

1.OA.A.1 Common Core Math

Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

How this material aligns: Step 6 has the class add Team Blue's litter count and Team Green's litter count together to find the combined total, an add-to word problem with the total unknown.

All materials for 1.OA.A.1 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-16.

Objectives

Students will sort litter items from natural items found near a model creek.
Students will count how many litter pieces their team collected.
Students will add both teams' counts together to find the total litter collected.

Vocabulary

Key words: litter, patrol, natural, total

Teacher overview

A strip of blue tape across the classroom floor stands in for Larkspur Creek, and twelve paper cutouts scattered nearby stand in for the mix of natural items and litter a real creek collects. In this activity, two teams patrol their side of the creek, picking up only the litter and leaving natural items alone, then the class combines both teams' counts into one total, connecting a hands-on cleanup with simple addition.

Activity Directions

Before class, scatter the twelve paper cutouts near the taped creek line: place four litter items (bottle, wrapper, can, foil) and two natural items on one side (Zone A) and three litter items (cup, straw, bag) and three natural items on the other side (Zone B), without telling students the split in advance.
Open with a short discussion: "Why is litter a problem for the plants and animals living near Larkspur Creek? What could we ask to learn more before cleaning it up?" Take a few student questions.
Split the class into Team Blue, which patrols Zone A, and Team Green, which patrols Zone B. Explain that teams should pick up litter items only, and leave natural items such as leaves, twigs, feathers, pebbles, and pinecones where they are, since those belong near a creek.
Set a five-minute timer. Both teams patrol their zone at the same time, placing litter items only into their own bin.
When time is up, each team counts how many litter pieces they collected and reports the number to the class.
As a class, add Team Blue's count and Team Green's count together to find the total litter collected from both zones.
Debrief: compare the combined total to the twelve items that were originally scattered, and discuss why leaving the natural items alone mattered.
Closure: agree on one class sentence about why creek patrols like this one help keep a creek healthy.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

Each answer is numbered to match the Activity Directions step it belongs to.

Answer: 4 litter pieces for Team Blue; Team Green collects 3 litter pieces. Team Blue's Zone A held four litter items: a bottle, a wrapper, a can, and foil. Team Green's Zone B held three litter items: a cup, a straw, and a bag.
Answer: 7 litter pieces in all. 4 + 3 = 7.
Answer: 5 natural items left in place. For the debrief question "How many of the twelve scattered items were natural items left in place?", there were two in Zone A and three in Zone B, since 12 total items minus 7 litter items equals 5 natural items. For the debrief question "Why did teams leave natural items alone?", answers will vary; accept a reasonable answer, such as leaves, twigs, feathers, pebbles, and pinecones already belong near a creek and are not a problem the way litter is.

Differentiation

Support

Show students a labeled sample of each litter item and each natural item before the timer starts, and allow teams to sort items into a "not sure" pile to review together with the teacher rather than guessing.

Extension

Ask each team to predict, before patrolling, how many litter items they think are in their zone, then compare their prediction to their actual count and explain any difference.

ELL supports

Pre-teach "litter," "patrol," "natural," and "total" using the physical paper cutouts, sorting one example of each into the correct bin together as a class before teams begin. Allow the debrief questions to be answered with a pointed finger or a single word.